Epidermal-Dermal Interactions in Normal and Diseased Adult Human Skin. We have established a model for long-term cultivation of adult human skin on nude athymic mice. This system is being utilized for the study of lamellar ichthyosis which can be grown on the nude mice for prolonged periods of time. Recombinant grafts composed of lamellar ichthyosis epidermis and dermis and normal epidermis and dermis have been used to investigate the site of the pathologic defect in this disease. These studies indicate that the defect is in the ichthyotic epidermis. Studies are planned to investigate other forms of ichthyosis and psoriasis in this system. Studies are also underway utilizing the skin-nude system to study conservation of regional epidermal maintenance. Basal cell carcinomas have been shown to grow for prolonged periods in this system. Further studies concerning the biological behavior of skin cancer are planned in this system. Formation of Structures at the Epidermal-Dermal Junction in Normal and Diseased Human Skin. Studies will be done to selectively extract structures at the epidermal-dermal junction in order to attempt their isolation, purification and characterization. BIBLIOGRAPHIC REFERENCES: Briggaman, R.A. Wheeler, C.E., Jr.: The epidermal-dermal junction. J. Invest. Derm. 65:71-84, 1975. Briggaman, R.A. and Wheeler, C.E., Jr.: Epidermolysis bullosa dystrophica-recessive: A possible role of anchoring fibrils in the pathogenesis. J. Invest. Derm. 65:203-211, 1975.